The present invention relates to a board process unit without the use of a holder or a supporting board by passing a tool of the board process unit between first upper and lower conveyers and second upper and lower conveyers and by contacting the tool with only the board.
In a prior numerical control unit, a head holding a tool is laterally moved along a beam, and a suction table is longitudinally moved to the moving direction of the head, whereby a process board suctioned on the suction table is processed by the tool of the numerical control unit.
However, in such numerical control unit, when the process board is suctioned on the suction table, and the process board is processed by the tool, the tool may pass through the process board. Therefore, when the process board is directly mounted on the suction table, the suction table is damaged by the tool. To avoid damage to the tool, a supporting board having suction holes which are the same as the suction table is mounted on the suction table, and the process board is mounted on the supporting board. Because the supporting board has the suction holes corresponding to the process board, when a different type of process board is mounted on the supporting board, the supporting board corresponding to the different type of process board must be mounted on the suction table. The work involved in changing the supporting board is troublesome, and the working performance is reduced.
It is, therefore, the primary object of the present invention to provide a board processing unit by which a process board can be processed without a supporting board.
It is another object of the present invention to provide a board processing unit in which the lower faces of the first and second upper carrying belts are constructed to be flat, the upper faces of the first and second lower carrying belts are constructed to be flat, and a process board is held and passed between the first and second upper carrying belts and the first and second lower carrying belts and is processed by a tool.
In order to accomplish the above and other objects, the present invention comprises a board processing unit including first and second upper conveyers including opposing small rollers having a small diameter, large rollers having a large diameter provided remote from the small rollers, respectively, a plurality of small flat rollers positioned between the small rollers and the large rollers, and belts wound around the small rollers, the large rollers and the plural small rollers; first and second servomotors having pulleys; belts wound around the pulleys and the large rollers of the first and second upper conveyers; first and second lower conveyers including small rollers provided lower than and near the small rollers of the first and second upper conveyers, middle rollers provided remote from the small rollers, large rollers provided lower than the middle rollers, a plurality of upper middle rollers positioned between the small rollers and the middle rollers, and belts wound around the small rollers, the middle rollers and the plural middle rollers; third and fourth servomotors having pulleys; belts wound around the large and middle rollers of the first and second lower conveyers; and first and second gear boxes having ball threads for raising and lowering the first and second upper conveyers, whereby a process board positioned on the first and second lower conveyers is pushed by the first and second upper conveyers lowered by the gear boxes, and the first and second upper conveyers and the first and second lower conveyers are synchronously driven by the first, second, third and fourth servomotors such that a tool attached above the first and second upper conveyers is passed between opposing portions of the first and second upper conveyers and the first and second lower conveyers and the process board is processed by the tool.